Elevated levels of breatheable ozone will reduce the amount of UV radiation in the range of 280-305 nm reaching the surface of earth. This range of UV converts the provitamin 7-dehydrocholesterol to vitamin D, within the human. Since most typical diets contain low levels of vitamin D, the role of UV related vitamin D synthesis in the skin is considered to provide very important contributions to the total vitamin D content of the blood. Thus, elevated levels of ambient ozone should result in a decreased level of vitamin D synthesis which may be expressed as an increase in the incidence of histological osteomalacia and ultimately bone fractures, especially among the elderly.